Abstract
In non-human primates, Captive breeding is important for ex situ conservation of endangered species and maintain captive
populations. On the other hand, limited space and pedigree management often necessitate the suppression of breeding. In
zoos, sex separation in captivity and surgical castration/contraception have been performed. However, in primates, separating
and keeping the animals in same-sex groups can lead to aggression issue due to space limitation. Furthermore, if an animal is
kept alone for sex separation, it can be stressful for the animal. On the other hand, surgical contraception is highly invasive and
irreversible, which may be problematic in terms of animal welfare. Therefore, synthetic progestin has been used in females as a
reversible contraception to mimic pregnancy, but alternative contraception methods are essential due to discontinuation of popular
progestin implants in the Japanese market and the risk of side effects caused by long-term progesterone exposure. Reproductive
and aggression suppression by controlling gonadotropin-releasing hormone (GnRH) has been conducted in zoos and aquariums
overseas. However, the appropriate usage/dosage foreach species is still unknown. To verify the effects of GnRH control on
reproduction and aggression suppression, GnRH vaccine and GnRH agonist are used, and the usage/dosage and their efficacy for
each species are evaluated. Moreover, establishing a database contraception by GnRH control is now being promoted through
collaboration with several facilities.
